Water Supply & DistributionQuestion 3 of 360
An air gap is used to protect a potable water outlet discharging into a fixture. What is the minimum required vertical air gap relative to the effective opening of the supply?
a.Equal to one-half the effective opening
b.Equal to the effective opening
c.At least two times the effective opening, but never less than 1 inch
d.Ten times the effective opening
Explanation
The code defines a minimum air gap as twice the effective opening (inside diameter) of the supply outlet, and in no case less than 1 inch. One-half or one times the opening is insufficient, and ten times is far more than the code minimum requires.
Law Reference: 2022 California Plumbing Code (CPC) §603.3.1Practice all 360 questions free — no signup required.
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